Multi-detectable ink compositions and method of use

ABSTRACT

Inks are disclosed wherein the ordinary mixed light color of the ink is a color substantially different than the fluorescent color of the ink. Methods of use include detection of at least the fluorescent wavelength of the ink or detection of both the ink colors when irradiated for fluorescence and by exposure to mixed light.

United States Patent [191 McDonough et al.

[ Dec. 23, 1975 1 1 MULTI-DETECTABLE INK COMPOSITIONS AND METHOD OF USE[75] Inventors: William F. McDonough, Trumbull;

James A. Montlick, Darien; Richard A. Bernard, Norwalk, all of Conn.

[52] US. Cl 252/30l.2 R; 106/21; 117/12; 250/461; 252/301.3 R [51] Int.Cl. C09D 5/22 [58] Field of Search 252/3012 R, 301.3 R; 106/21 [56]References Cited UNITED STATES PATENTS 2,763,785 9/1956 Switzer 252/3012R 2,938,873 5/1960 Kazenas 252/3012 R 2,950,050 8/1960 Mazer et al252/3012 R 3,066,105 11/1962 McCafferty 252/3012 R 3,198,741 8/1965Kazenas 252/3012 R 3,303,168 2/1967 Kazenas 252/3012 R 3,412,035 ll/1968McIntosh et al. 252/3012 R 3,455,856 7/1969 Voedisch et al. 252/3012 R3,518,205 6/1970 Vukasovich 252/3012 R 3,560,238 2/1971 Rothery 106/213,741,907 6/1973 Beyerlin 252/3012 R 3,804,774 4/1974 Betts et al.252/3012 R Primary Examiner-Arthur P. Demers Attorney, Agent, orFirm-William D. Soltow, Jr.; Albert W. Scribner; Peter Vrahotes [57]ABSTRACT Inks are disclosed wherein the ordinary mixed light color ofthe ink is a color substantially different than the fluorescent color ofthe ink. Methods of use include detection of at least the fluorescentwavelength of the ink or detection of both the ink colors whenirradiated for fluorescence and by exposure to mixed light.

4 Claims, No Drawings In the machine processing of various types ofinformation contained on ticke'ts, tags, labels, postage imprints andthe like it is generally known to employ v detectors which areresponsive to shape'relationships and/or colors, and in manycases tothe-fluorescence of an ink which may be excited, for example, byultraviolet light. Fluorescent inks and dyes have long been known as,for example, those disclosed in- U.S., Pat. Nos. 2,681,317; 2,763,785;3,230,221; 3,412,104; 3,452,075; and 3,560,238. 'The fluorescent inksand the, methods of making or using them as known in the prior art,generally'entail the use of a fluorescent ink which, when irradiated,will fluo'resce and emit radiation within the wavelength-for theparticular fluorescent color of that dye o r'ink.-'It is known, forexample, in the postage meter art to provide a red fluorescent ink formachine reading of processed mail.

The fluorescent detectors, however, are generally designed or set topick up'e'missions only within a certain range of wavelengthsandaccordirigly, the coloration of the ink will be dependent upon theformulation which provides for fluorescence under light such asultraviolet light, to emit radiation of a certain wavelength. i

It is desirable, however, toprovide tickets, tags, labels, postage meterimprints, stampings, or the like with a greater variety of visual colorfor classification, for inventory purposes or sorting, for example, sothat the tags, tickets, envelopes and the like are, or may be, processedvisually by people, as well as by one or more machines. A problemarises, however, when a variety of visual colors are used since thevisual color is generally related to the fluorescent color of the inkwhen it is irradiated. Thus, if there is a mixture of different tags,tickets, or letters which are to be machine read, the machine must beresponsive to a broad spectrum of emission wavelengths or the machinemust be adjusted to receive the wavelengths of the various fluorescentink colors as they are processed.

Accordingly, it is an object of the invention to provide means forhaving two different colors contained in the same ink, one an ordinarymixed light color and the other a fluorescent color.

2 gels and/or antioxidantsiThe ink compositions are made from acombination of pigments including daylight fluorescent pigmentswhich aresolid solutions'of fluorescent dyes in friable organic resins. Thus thepigment combinations provide a variety of colors to the eye or to anoptical reader, but all provide'for fluorescent emission within arelatively narrow wavelength to make it possible to machine readtickets, labels, mail or the like with a single setting of a fluorescentdetector device while providing for a variety of visually differingcolors in accordance with the method of the invention. The visualdiffering colors can be also optically read by a machine to provide asecond mark'or set of data from that read by the fluorescentdetectornThe visual'color .,of the ink is a color other than red whilethe fluorescent color of the ink is preferablyred ororange-red.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION cies and afluorescent radiation color which'whe'n irradiated with ultravioletlight, for example, fluoresces preferably in the red wavelength of aboutfrom 5 800 A to 6200 A. Since there are existing machines for readingfluorescent ink imprinted information, a variety of visual colors can beemployed with the fluorescent color of the ink being within the redportion of the spectrum. Thus the ink imprint may be read visually or bysome other type of optical machine reader and then read by a fluorescentmachine reader which is set to pick up the fluorescent wavelength of theink. This is particularly useful in the field of postage imprintingsince at large postal installations machines may be available to readpostage information, but at many smaller or rural stations the postageimprint must be visually read. Further, by the use of a visual oroptical color which is different from the fluorescent color acombination of information may be imprinted which is readable by twodifferent machines, i.e. an optical reader which is responsive to thereflected color and/or shape of the imprintunder ordinary mixed lightand a fluorescent reader which responds to the particular fluorescentwavelength when the ink is irradiated.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises a method and a composition of matterpossessing the characteristics, properties, and the relation ofcomponents which will be exemplified in the composition and the methodof use thereof hereinafter described, and the scope of the inventionwill be indicated in the claims.

SUMMARY OF THE INVENTION cent pigments with 0.3 to 10 percentnon-fluorescent pigments in a vehicle which contains surfactants and Theinks may have ordinary mixed light colors of orange, brown, purple,black, blue or green, for example, while emitting orange-redfluorescence when activated by long or short ultraviolet waves. Thegeneral formulation is a'combination of fluorescent and optical pigmentswith the fluorescent pigments comprising about 2 to 25 percent andpreferably about 10 to 20 percent by weight with the non-fluorescentpigments making up from about 0.3 to 10 percent and preferably from 0.5to 2.5 percent by weight of the ,ink formulation. The pigments arecarried in a vehicle which comprises about to percent of the ink byweight and preferably comprises a mixture of dioctyl phthalate and analiphatic hydrocarbon havinga distallation range of about 310 to 345C,which is sold by East Coast Chemicals Co. as Escoflex 175. The ratioof-dioctyl phthalate to the aliphatic hydrocarbon is about 3:1 byweight. To the vehicle there is added about 0.25 to 1.5 percentsurfactant and about 0.25 to 5 percent gellant all by weight. Thepreferred surfactant'is lecithin and the preferred gellant is aluminumstearate having a high free stearic acid content made up as a 10 percentgel in 3 a vehicle which is the same or is compatible with the inkvehicle. There may also be added up to about 1 percent antioxidant andthe preferred antioxidant is eugenol.

The fluorescent pigments are dispersions in a heat-set type vehiclewhich comprises, for example, a suitable resin dissolved in a highboiling narrow fraction hydrocarbon solvent or are dispersions of thefluorescent pigments in a drying type alkyd resin such as Trionol No. 3sold by Lawter Chemicals, Inc. The fluorescent pigments are solidsolutions of fluorescent dyes in friable organic resins. A typicalexample would be a powdered thermo-plasticmelamine-sulfonamide-formaldehyde resin which contains various dissolvedfluorescent dyes wherein the resin is the matrix for the dye. Thedaylight fluorescent pigments preferred are thus modified sulfonamideresins containing fluorescent dye or dyes in solid solution. The otherpigments used as set forth in the Examples below are used to impart thedesired visual color which is substantially different from thefluorescent color under ultraviolet light. The visual pigments aregenerally in a heat-set type vehicle, a litho varnish or a mixture ofdioctyl phthalate and an aliphatic hydrocarbon having a distillationrange of about 310C to 345C in a ratio of about 3: l. This is set forthas PRV (porous roller vehicle) in the Examples are weighed into a tengallon tank and mixed to form the vehicle solution. The gel(s) andpigments are then weighed into a twenty gallon mixing vessel and blendedwith a mixer such as a Cowles mixer until the mixture is uniform whichshould take about 15 to 20 minutes. If there are any undispersed gels orpigments the stirring should continue until the mixture is uniform. Thegel pigment dispersion is continued to be stirred and 1%: to 2 gallonsof the vehicle solution is added to the dispersion and is stirred for aperiod of about 5 to 10 minutes before the addition of the remainingvehicle solution. The ink is then stirred for about minutes more and isthen strained through four to six layers of cheesecloth before it is runon an Eppenbach high-speed mixer for about 15 minutes. The ink is thenallowed to stand for 10 hours or more (such as over night) and is thenstirred for about 15 minutes with a propeller mixer and again for 15additional minutes with a high-speed mixer, again allowed to stand forover 10 hours and is then stirred once more with a propeller mixer,after which it is ready for use.

EXAMPLE II The procedure for preparing the ink in this Example is thesame as that set forth in Example I, above, except that the formulationis as follows:

by Weight By Commercial in Ink (incl. Brown Weight Designation vehicle)Source High Intensity Yellow Orange l3.98 H61 l8 Dispersion 27.96 LawterChem. Carbon Black 0.87 W-92 Flush 3.06 Chemetron Corp. PhthalocyanineGreen 0.15 5-65-F-423 Flush 0.43 Hilton Davis Div.

Sterling Drug, Inc. Aluminum Stearate I32 0.50 l0% Gel in PRV 5.00Lecithin U.F. 0.50 Lecithin U.F. 0.50 Eugenol 0.25 Eugenol U.S.P. 0.25Vehicles 83.75 DOP PX-l38 47.I0 Escoflex I 15.70

below.

The following Examples are exemplary of the inven- EXAMPLE tion andshould not be considered limiting. The procedure for preparing the inkin this Example EXAMPLE I By Weight By Weight Commercial in Ink (incl.Orange in Ink Designation vehicle Source Strong Red Orange 7.70 D516Dispersion 15.40 Lawter Chemicals, Inc. Benzidine Yellow I.50 PS1 I I7Thermex Flush 6.00 Chemetron Corp. Brilliant Toning Red 0.80 FL-l0-707PRV Flush I.77 Sherwin Williams Chemicals Aluminum Stearate [32 0.50 I0%Gel In PRV 5.00 Witco Chemical Corp. Polyvinyl Chloride 0.12 Marvinol 5O3% Gel In PRV 4.00 Uniroyal. Inc. Lecithin U.F. 0.50 Lecithin U.F. 0.50A. E. Staley Mfg. Co. Eugenol 0.50 Eugenol U.S.P. 0.50 Fritzsche Dodge &Alcott. Inc. Vehicles 88.38 DOP PX-l38 50.13 US. Steel Corp. ChemicalDiv. Escoflex I75 l6.7l East Coast Chemicals Co.

The procedure used for a pound batch of ink in accordance with thisExample is as follows. First the Dioctyl Phthalate, Escoflex 175,Eugenol and Lecithin is the same as that set forth in Example I, above,except that the formulation is as follows:

Purple Pink 18.52 H622 Dispersion 37.04 Lawter Chemicals Alkali BlueG.G. 0.37 FL-15-403 Flush 1.09 Sherwin- Williams Aluminum Stearate 0.5010% Gel in PRV 5.00 Lecithin US. 0.50 Lecithin U.F. 0.50 Eugenol U.S.P.0.25 Eugenol U.S.P. 0.25 Vehicles 79.86 DOP PX-138 42.09

Escoflex 175 14.03

versus the constituentlus vehicle which is admixed to EXAMPLE IV p Theprocedure for preparing the ink in this Example that the formulation isas follows: 7

make the ink composition.

In the above Examples the aluminum stearate 132 has a high free stericacid content and the polyvinyl chloride used had an inherent viscosityof 1.20 and a By Weight By Commercial in Ink (incl. Black WeightDesignation Vehicle) Source Strong Yellow Orange 17.09 H618 Dispersion34.18 Alkali Blue (3.6. 0.73 FL-l5403 2.15 Aluminum Stearate 132 0.5010% Gel in PRV 5.00 Lecithin U.F. 0.50 Lecithin U.F. 0.50 Eugenol U.S.P.0.25 Eugenol U.S.P. 0.25 Vehicles 80.93 DOP PX-138 43.44

Escoflex 175 14.48

EXAMPLE V The procedure for preparing the ink in this Example is thesame as that set forth in Example 1, above, except that the formulationis as follows:

Blue Strong Red 9.00 H636 Dispersion 18.00

Phthalocyanine Blue 1.00 FS1116 Flush 3.57 Aluminum Stearate 0.50 10%Gel in PRV 5.00 Lecithin U.F. 0.50 Lecithin U.F. 0.50 Eugenol 0.25Eugenol U.S.P. 0.25 Vehicles 88.75 DOP PX-138 54.51 Escoflex 175 18.17

EXAMPLE VI The procedure for preparing the ink in this Example is thesame as that set forth in Example 1, above, except that the formulationis as follows:

specific viscosity of 0.50. The carbon black in the above Examples maybe any suitable pigment black, and for the above Examples the carbonblack was dispersed in a gloss-type vehicle. The non-fluorescentpigments are known such as benzidine yellow which is Lawter ChemicalsChemetron a common yellow pigment whichis flushed in a heat-set 45 typevehicle. The brilliant toning redpigment is also identified as PermanentRed 2B (Color Index 15865 Pigment Red 48) which is flushed in porousroller vehicle. The phthalocyanine Green is Pigment Green 7 In the aboveExamples the same constituents contain a fraction of solids by weightwhich accounts for the differences in the percentages of the constituentalone (Color Index 74260) which is flushed in a litho varnish. It isdesignated by the supplier (Hilton Davis) as Synthaline Green. TheAlkali Blue GG is a well known Pigment Blue 19 (Color Index 42750A)which is also 7 flushed in a litho varnish. The Phthalocyanine Blue isPigment Blue 15 (Color Index 74160) which is flushed in a heat-set typevehicle.

The ink can be applied in a number of ways by stamps, from rollers or byan appropriate printing device. While fluorescent wavelengths of otherthan red or red-orange may be employed, a red or red-orange is preferredsince there are existing detectors which are colors may be imprinted,but will all be machine readable by at least the same fluorescentdetector.

In practice, for example, when used for postage imprinting the ink maybe carried on or in rollers, belts,

pads, or the like for transferring the proper print configuration to aletter or postage imprint tape. Once imprinted the mail-carrying imprintwith such ink can be checked visually by the human eye or, dependingupon the postage imprint configuration, by an optical detector which maybe activated by the reflection of ordinary mixed light from the postageimprint. The same or other portions of the postage imprint may befurther read by a fluorescent detector when the postage imprint issubjected to, for example, ultraviolet radiation. Additional informationcontained in the postage imprint can be picked up by the fluorescentdetector. Mail sorting and routing, as well as the machine verificationof postage amounts and other such functions, can be facilitated by thedual emissive ink in accordance with theinvention. Similarly, the methodof the invention may be employed in the marking of retail price ticketsand the like to provide dual emissive characteristics for machinesorting and/or compilation of sales or inventory information.

The ink may also be used to verify the source of products. Phonographrecords, for example, may be marked with the dual emissive ink and bydetection of the fluorescent color by the human eye or by machine,counterfeit records may be separated from the genuine ones. The inkmayalso be used in decorative displays wherein by changes from mixedlight to fluorescent the design made with suchan ink would change.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained andsince certain changes may be made in the above methods or in thecompositions and formulations without departing from the scope of theinvention, it is intended that all matter contained in the abovedescription shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

*1. A machine-readable marking ink composition having two or more mixedpigments for processing and distinguishing articles both visually andunder radiation of a discrete predetermined wavelength, comprising A.from 0.5 to 10 percent non-fluorescent pigment by weight;

B. from 2.0 to 25.0 percent fluorescent pigment by weight whichfluoresces under radiation at a predetermined wavelength,

1. said fluorescent pigment being taken from the group consisting of a.fluorescent pigment dispersions in a vehicle which comprises a resindissolved in a narrow fraction petroleum distillate having a boilingrange of from about 440F. to 510F.,

b. fluorescent pigment dispersions in a drying type alkyd resin, or

c. comminated solid solutions of fluorescent dyes in modifiedsulfonamide resins;

C. from 0.25 to 1.5 percent surfactant by weight;

D. from 0.25 to 5 percent gellant by weight; and

E. all of said pigments, said surfactant and said gellant being in avehicle for the mixed pigment systern,

1. said vehicle consisting essentially of a mixture of a. dioctylphthalate and b. an aliphatic hydrocarbon having a distillation range ofabout 310C. to 345C, whereby the color of the ink under mixed light isdifferent than the fluorescent color of the ink when irradiated at thefluorescent wavelength of said fluorescent pigment.

2. The machine-readable marking ink of claim 1 wherein the fluorescentwavelength of said fluorescent pigment is from 5800 A to 6200 A.

3. The machine-readable marking ink of claim 1 wherein said surfactantis lecithin and said gellant is aluminum stearate.

4. The machine-readable marking ink composition defined in claim 1wherein said vehicle consists substantially of a mixture of said dioctylphthalate and said aliphatic hydrocarbon in a ratio of about 3:1.

1. SAID FLUORESCENT PIGMENT BEING TAKEN FROM THE GROUP CONSISTING OF AFLUORESCENT PIGMENT DISPERSIONS IN A VEHICLE WHICH COMPRISES A RESINDISSOLVED IN A NARROW FRACTION PETROLEUM DISTILATE HAVING A BOILINGRANGE OF FROM ABOUT 440*F. TO 510*F., B. FLUORESCENT PIGMENT DISPERSIONSIN A DRYING TYPE ALKYD RESIN, OR C. COMMINATED SOLID SOLUTIONS OFFLUORESCENT DYES IN MODIFIED SULFONAMIDE RESINS; C. FROM 0.25 TO 1.5PERCENT SURFACTANT BY WEIGHT; D. FROM 0.25 TO 5 PERCENT GELLANT BYWEIGHT; AND E. ALL OF SAID PIGMENTS, SAID SURFACTANT AND SAID GELLANTBEING IN A VEHICLE FOR THE MIXED PIGMENT SYSTEM, I. SAID VEHICLECONSISTING ESSENTIALLY OF A MIXTURE OF A. DIOCTYL PHTHALATE AND B.ANALIPHATIC HYDROCARBON HAVING A DISTILLATION RANGE OF ABOUT 310*C. TO345*C., WHEREBY THE COLOR OF THE INK UNDER MIXED LIGHT IS DIFFERENT THANTHE FLUORESCENT COLOR OF THE INK WHEN IRRADIATED AT THE FLUORESCENTWAVELENGTH OF SAID FLUORESCENT PIGMENT.
 1. A MACHINE-READABLE MARKINGINK COMPOSITION HAVING TWO OR MORE MIXIED PIGMENTS FOR PROCESSING ANDDISTINGUISHING ARTICLES BOTH BISUALLY AND UNDER RADIATION OF A DISCRETEPREDETERMINED WAVELENGTH, COMPRISING A. FROM 0.5 TO 10 PERCENTNON-FLUORESECENT PIGMENT BY WEIGHT; B. FROM 2.0 TO 25.0 PERCENTFLUORESCENT PIGMENT BY WEIGHT WHICH FLUORESCES UNDER RADIATION AT APREDETERMINED WAVELENGTH,
 2. The machine-readable marking ink of claim 1wherein the fluorescent wavelength of said fluorescent pigment is from5800 A to 6200 A.
 3. The machine-readable marking ink of claim 1 whereinsaid surfactant is lecithin and said gellant is aluminum stearate. 4.The machine-readable marking ink composition defined in claim 1 whereinsaid vehicle consists substantially of a mixture of said dioctylphthalate and said aliphatic hydrocarbon in a ratio of about 3:1. .